The Only Constant is Change: Incorporating Time-Varying Network Reservations in Data Centers

摘要

In multi-tenant datacenters, jobs of different tenants compete for the shared datacenter network and can suffer poor performance and high cost from varying, unpredictable network performance. Recently, several virtual network ions have been proposed to provide explicit APIs for tenant jobs to specify and reserve virtual clusters (VC) with both explicit VMs and required network bandwidth between the VMs. However, all of the existing proposals reserve a fixed bandwidth throughout the entire execution of a job. In the paper, we first profile the traffic patterns of several popular cloud applications, and find that they generate substantial traffic during only 30%-60% of the entire execution, suggesting existing simple VC models waste precious networking resources. We then propose a fine-grained virtual network ion, Time-Interleaved Virtual Clusters (TIVC), that models the time-varying nature of the networking requirement of cloud applications. To demonstrate the effectiveness of TIVC, we develop PROTEUS, a system that implements the new ion. Using large-scale simulations of cloud application workloads and prototype implementation ninning actual cloud applications, we show the new ion significantly increases the utilization of the entire datacenter and reduces the cost to the tenants, compared to previous fixed-bandwidth ions.